Hi, I'm Emiko

I am a third-year graduate student at UC Berkeley and a member of NANOGrav, working with Prof. Luke Kelley researching nanohertz gravitational waves (GWs) from supermassive black hole binaries (SMBHBs). My research interests more broadly including black holes, cosmology, and gravitation. A list of my publications is available here.

I graduated from University of Virginia in 2022 with a BS in Physics and Engineering Science (Physics+CS BYO degree). There, I researched massive protostellar outflows and X-shaped radio galaxies, played on the Virginia Women's Rugby Team (go Flos!), and was primarily involved in Sigma Pi Sigma and Rodman Council (details in my CV).

I now spend most of my time in Campbell Hall or coding in my favorite coffee shop, while blasting EDM through my earbuds (dubstep when version control issues get frustrating). I also enjoy yoga, running, crocheting, any kind of puzzle, and the occassional art project.

nHz Gravitational Waves

  • Continuous Waves

    SMBHBs at small separations are theorized to produce continuous GWs (CWs) at nanoHertz frequencies. The superposition of many CWs results in a stochastic background, for which current pulsar timing arrays (PTAs) have found strong evidence. I model populations of SMBHBs with holodeck to forecast single source CW detections, depending on astrophysical models.

  • GWB Anisotropy

    Before individual CWs are detected, we expect to measure louder and quieter regions of the GW sky deviating from a completely isotropic background. I calculate the level of anisotropy from holodeck SMBHB populations through spherical harmonic decomposition, and have found median predictions to fall among current upper limits ( NG15 anisotropy paper ).

Past Astronomy Research

Ionization in Massive Protostellar Outflows

The mechanism behind massive star formation is still under debate and is difficult to observe because massive stars form in distance, crowded environments. However, we can study their bipolar outflows whose bright radio emissions penetrate the surrounding gas and dust. As an undergraduate research fellow in the Virginia Initiative on Cosmic Origins (VICO) advised by Jonathan Tan, Jan Staff, and Jon Ramsey, I developed a post-processing pipeline for shock ionization in Jan Staff's 3D MHD simulation of a disk-wind driven massive protostellar outflow. We focus on shock ionization because this causes strong radio emissions where fast (~1000km/s) outflowing gas collides with the surrounding, slower-moving envelope. We also investigate the role of photoionization, which dominates when the protostar becomes sufficiently bright (around ~15Msun) to ionize the outflow cavity.

Poster PDF Paper
X-shaped radio galaxy shown in 1.4GHz, 3GHz, and r-band tricolor. iPoster

X-Shaped Radio Galaxies Hosting SMBHBs

X-shaped radio galaxies are a rare phenomenon in which galaxies with bright radio lobes have a second set of dimmer radio-visible wings, forming and X-shape. One scenario to explain these wings is that they are relic emissions from a previous spin orientation, which could have been reoriented due to binary interactions between dual SMBHs. Under the advisorship of Ilsang Yoon and Bjorn Emonts, at the National Radio Astronomy Observatory, I searched for signatures of binary SMBHBs among all known X-shaped Radio Galaxies.

Outreach

Society for Women in Physical Sciences (SWPS) @ Berkeley, Grad Coordinator

Physical sciences Opportunities for Women in Education & Research (POWER) Bay Area , Mentor

One of my favorite parts of research is the opportunity to travel, and document said travel with my iPhone camera. You can find some of my amateur photography here.